Gouache paints used in many people, from the old man, down to the child and the old man painting and character cultivation, children drawing with it to develop fun. Elderly, children's skin is very fragile and that gouache to have their skin injuries?
Gouache is mainly made of pure natural plant gum and high quality colour powder, through ultra fine grinding fine becomes. Rest of ingredients are not toxic, but there is some preservatives, we smell issue may be preservatives or flour ingredients asked. This is harmful to the human body. But I think it should be no problem if you don't eat.
Gouache is not going to have an impact on the skin, it is tailored for the disciplines of graphic design of a product that conforms to EN71 standard, safety, environmental protection and health.